Branchiodrilus hortensis, an exotic worm new for the Dutch fauna (Annelida: Oligochaeta)The peculiar naidid worm Branchiodrilus hortensis (Stephenson, 1910) is recorded new for theNetherlands. In 2002 and 2003 several specimens were collected from three localities in and nearthe Giessen, a small, slow-flowing river near Gorinchem (province of Zuid-Holland). In 2004numerous specimens were collected in the small river Aa in the city of Den Bosch (provinceof Noord-Brabant). These freshwater localities (Cl 50-143 mg/l) are eutrofic, slightly alkaline(pH 7.3-8.6) and with a reasonable oxygen-level (saturation > 70%). Branchiodrilus hortensis isknown from southern Asia, Australia and Africa. It is not known how this species has becomeintroduced into the Netherlands, but exotic water plants from gardens are a likely vector. Theserecords are the first in Europe.